The goal of the proposed research is to prepare the applicant for an academic research career and, more specifically, to enable her to understand and study the social environmental factors, normative factors, and social network characteristics that are related to health behaviors that contribute to overall longevity and quality of life among persons living with HIV/AIDS (PLWHA). The proposed research will be implemented in the context of a comprehensive training program that has the following objectives: 1) to develop content knowledge in the application of social network analysis to public health research examining health behaviors among PLWHA; 2) to develop a methodological foundation in the combined use of self-reported social network and clinical biological data for addressing important research questions; and 3) to engage in the dissemination of research findings and networking with the broader research community examining the intersection of HIV, cigarette smoking, and medication adherence. PLWHA face a variety of health-related complications, in addition to HIV infection itself. Despite the deleterious health consequences, an overwhelming majority of PLWHA are cigarette smokers. Additionally, poor adherence to medication regimens has implications for poor health outcomes for the affected individuals, in addition to the potential for increased transmission of HIV. The bulk of existing research has focused on the examination of individual-level factors and characteristics that are influential of health behaviors among PLWHA. Additional research is needed to assess the degree to which social environmental and normative factors, as well as social network characteristics are associated with these behaviors, in order to gain a more comprehensive understanding of the processes that influence performance of heath behaviors. These findings will likely help to inform the development of targeted interventions and preventive efforts aimed at improving the quality of life and extending overall longevity of life of PLWHA. The proposal will address these issues via the following questions: 1) To what extent are social environmental and normative factors, and social network characteristics associated with smoking behaviors among PLWHA?; 2) To what extent are social environmental and normative factors, and social network characteristics associated with psychiatric and HIV medication adherence among PLWHA?; and 3) To what extent is smoking associated with HIV medication adherence among PLWHA and what are the factors confounding that relationship?. These questions will be investigated via an in-depth examination of data collected in Baltimore City, Maryland from an urban, HIV-positive, current or former injection drug using sample. This project is aligned with the objectives of the National Institute on Drug Abuse in that it will address research gaps relative to health behaviors among HIV-positive current and former substance users.